Forms and documentation
Imaging and biomarker data are available on a subset of UDS participants. These data are most appropriately described as a convenience sample, voluntarily submitted by several Alzheimer’s Disease Research Centers (ADRCs). The imaging available on a subset of UDS participants is primarily MRI and associated volumetric data. Biomarker data is in the form of CSF values for Abeta, P-tau, and T-tau. Limited genetic data is available at NACC (i.e., APOE genotype, recorded for more than 75% of participants); more genetic data are available from our partners.
Researcher’s Data Dictionary — Imaging Data (RDD-ID)
The Researcher’s Data Dictionary — Imaging Data (RDD-ID) includes MRI and PET variables (e.g., year of MRI scan, year of amyloid PET scan) associated with DICOM files stored at NACC. Also included are MRI variables that provide volume values (e.g., hippocampal volume) for the subset of DICOM files stored at NACC for which volumetric analysis has been completed. Imaging data collection and acquisition protocols vary by ADRC, Packages of MRI files at NACC may include T1-weighted, FLAIR, DTI, T2, or other MR series (and any combination thereof). Participants may also have MRI or PET scans from multiple dates.
For a subset of the MRIs, calculated summary data are also available. The calculations were performed by then IDeA Lab (Director: Charles DeCarli, MD; University of California, Davis), following ADNI protocols. For specific methods used to perform these calculations, please see this document provided by the IDeA Lab.
An older version of the RDD-ID is also available for researchers using data sets that include variables that were available from 2015 to May 2019.
Data Element Dictionary — CSF (DED-CSF)
The Data Element Dictionary — CSF (DED-CSF) includes data on UDS participants who have CSF values for Abeta, P-tau, and T-tau. Please note that CSF assay methods are not standardized across the ADRCs, and that some participants may have CSF values from multiple dates.
Researcher’s Data Dictionary — Genetic Data (RDD-Gen)
The Researcher’s Data Dictionary — Genetic Data (RDD-Gen) describes variables that contain either genetic data (APOE genotype) or information about the availability of genetic data that can be obtained, by request, from the Alzheimer’s Disease Genetics Consortium (ADGC), or the National Institute of Aging Genetics of Alzheimer’s Disease Data Storage Site (NIAGADS).